Effect of poly(ethylene glycol) on the properties and foaming behavior of macroporous poly(lactic acid)/sodium chloride scaffold

Abstract

In this study, we prepared poly(lactic acid) (PLA)/poly(ethylene glycol) (PEG)/sodium chloride (NaCl) blends by melt blending with a triple‐screw dynamic extruder. The effects of PEG on the thermal property, mechanical property, and morphology of blends were investigated in detail. It was found that the incorporation of PEG and NaCl significantly improved the crystallization rate, elongation at break, surface adhesion, and reduced viscoelasticity of PLA. The blends were further batch‐foamed at different temperatures with supercritical carbon dioxide to study the foaming properties. The results of PLA/PEG/NaCl (50 : 10 : 40 wt %) composites after foaming and particle leaching revealed that an interconnected bimodal porous scaffold with the highest porosity of 89% could be achieved. Furthermore, the addition of PEG can significantly reduce the water contact angle so as to enhance the wetting ability of the scaffolds. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41181.

Engineering Porous Poly(lactic acid) Scaffolds with High Mechanical Performance via a Solid State Extrusion/Porogen Leaching Approach

“…Consistent with a previous report [40], rinsing out water-soluble PEG is in favor of improving pore interconnectivity (Figure 3b). All the porous PLA scaffolds exhibit high connectivity in excess of 97%.…”

“…An integrated structure is a necessary prerequisite for PLA scaffolds to prevent premature collapse and to promote bone tissue regeneration in vivo . As evidenced by the existing literatures, inclusion of NaCl component depresses the chain mobility of PLA and results in inferior flowability [40]. Our preliminary exploration also found that there were visible cracks on the surface of PLA/NaCl extrudates; subsequently, the binary blends collapsed irreparably during the leaching process due to structural defect.…”

“…Pleasingly, in our study, even the as-prepared scaffold materials containing NaCl amounts more than 80.00 wt % were extruded favorably, as presented in Figure 2a. This is because the presence of PEG in the ternary blends is conducive to a decrease in viscosity and the improvement in flowability [40]. Further evidence for good structural integrity can be furnished from leached P 80-20 , as visualized in Figure 2b.…”

Reactive extrusion of bio-based polymer blends and composites – Current trends and future developments

“…This is due to its high costs related to complicated screw geometry and barrel construction, comparing to single-or twin-screw extruders. Nevertheless, recently triple screw extruders were successfully applied for preparation of biobased materials, such as microcellular poly(lactic acid)/talc biocomposites [38], poly(lactic acid)/poly (vinyl alcohol) blends [39] or poly(lactic acid)/poly (ethylene glycol) porous scaffolds [40][41][42]. In our opinion, application of triple-screw extrusion during reactive extrusion of 'conventional' and biodegradable polymers will be developing in near future.…”

Polylactic Acid Based Nanocomposites: Promising Safe and Biodegradable Materials in Biomedical Field

“…PLA based nanocomposites, which include PLA based copolymers in nanometer size and nanocomposites with PLA or PLA copolymers as matrix and nanofillers as annexing agent, have shown great potential in biomedical field [26]. The small scale effect and surface effect nanomaterials have particularly helped improve the properties of PLA and make PLA based nanocomposites more popular compared with pure PLA materials when it comes to synthetic bone substitute and repair, tissue engineering, and drug delivery system.…”